I had the EZ Super Chipmunk when I really hadn't developed the skill to fly that kind of airplane... paired it with the then newly released, O.S. four cycle FS-.61 which I don't think was a good match even though M.A.N. featured a promo review article by Chris Chianelli (IIRC) with the same combo. If you pulled too hard on elevator at the top of a loop, it would snap out. I pulled too much up elevator during a low and slow, final approach to the runway when the engine quit, tried to stretch the glide, and airplane tip-stalled very quickly into low lying brush destroying the wing.

A few years later, I bought another - this time powered it with a 2-stroke .61 FSR and the airplane now had the vertical performance that was lacking with the first. I was so anal about shifting weight during gear retraction (fore/aft operation rather than conventional) that I substituted the stock wheels with Ace lightweight plastic wheels (the tires were hollow plastic) to reduce any CG shift and servo strain between gear down, gear up. I remember some of the airplanes featured a servo tray that allowed the user to select distribution of equipment according to engine choice. Flew it a few years but on last flight - flamed out abreast, was too far out with the crosswind at my back, and stuck it in the top of a line of trees I was trying to clear.